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Related papers: Exciton thermalization dynamics in monolayer MoS2:…

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We have investigated the exciton dynamics in transition metal dichalcogenide mono-layers using time-resolved photoluminescence experiments performed with optimized time-resolution. For MoSe2 monolayers, we measure $\tau_{rad}=1.8\pm0.2$ ps…

Materials Science · Physics 2016-05-18 C. Robert , D. Lagarde , F. Cadiz , G. Wang , B. Lassagne , T. Amand , A. Balocchi , P. Renucci , S. Tongay , B. Urbaszek , X. Marie

Exciton dynamics dictate the evolution of photoexcited carriers in photovoltaic and optoelectronic devices. However, interpreting their experimental signatures is a challenging theoretical problem due to the presence of both electron-phonon…

Temperature influences the performance of two-dimensional materials in optoelectronic devices. Indeed, the optical characterization of these materials is usually realized at room temperature. Nevertheless most {\it ab-initio} studies are…

Mesoscale and Nanoscale Physics · Physics 2016-06-06 Alejandro Molina-Sánchez , Maurizia Palummo , Andrea Marini , Ludger Wirtz

Newly measured optical absorption and photoluminescence spectra reveal substantial frequency shifts of both exciton and trion peaks as monolayer MoS2 is cooled from 363 K to 4 K. First-principles simulations using the GW-Bethe-Salpeter…

Mesoscale and Nanoscale Physics · Physics 2014-05-22 Ryan Soklaski , Yufeng Liang , Changjian Zhang , Haining Wang , Farhan Rana , Li Yang

Transition metal dichalcogenides layered nano-crystals are emerging as promising candidates for next-generation optoelectronic and quantum devices. In such systems, the interaction between excitonic states and atomic vibrations is crucial…

Mesoscale and Nanoscale Physics · Physics 2023-12-29 Jianbo Hu , Yang Xiang , Beatrice Matilde Ferrari , Emilio Scalise , Giovanni Maria Vanacore

We examine a mechanism by which excitons undergo ultrafast relaxation in common monolayer transition metal dichalcogenides. It is shown that at densities $\approx$ 1$\times$ 10$^{11}$ cm$^{-2}$ and temperatures $ \le 60$ K, excitons in well…

Mesoscale and Nanoscale Physics · Physics 2016-06-29 A. Thilagam

We examine a mechanism by which excitons are generated via the LO (longitudinal optical) phonon-assisted scattering process after optical excitation of monolayer transition metal dichalcogenides. The exciton formation time is computed as a…

Materials Science · Physics 2016-10-12 A. Thilagam

Atomically thin layer transition metal dichalcogenides have been intensively investigated for their rich optical properties and potential applications in nano-electronics. In this work, we study the incoherent optical phonon and exciton…

We report on the exciton and trion density dynamics in a single layer of MoSe$_2$, resonantly excited and probed using three-pulse four-wave mixing (FWM), at temperatures from 300K to 77K . A multi-exponential third-order response function…

Mesoscale and Nanoscale Physics · Physics 2017-07-12 L. Scarpelli , F. Masia , E. M. Alexeev , F. Withers , A. I. Tartakovskii , K. S. Novoselov , W. Langbein

By implementing four-wave mixing (FWM) micro-spectroscopy we measure coherence and population dynamics of the exciton transitions in monolayers of MoSe$_2$. We reveal their dephasing times T$_2$ and radiative lifetime T$_1$ in a…

We study experimentally and theoretically the exciton-phonon interaction in MoSe2 monolayers encapsulated in hexagonal BN, which has an important impact on both optical absorption and emission processes. The exciton transition linewidth…

A direct band gap, remarkable light-matter coupling as well as strong spin-orbit and Coulomb interaction establish two-dimensional (2D) crystals of transition metal dichalcogenides (TMDs) as an emerging material class for fundamental…

The equilibrium and non-equilibrium optical properties of single-layer transition metal dichalcogenides (TMDs) are determined by strongly bound excitons. Exciton relaxation dynamics in TMDs have been extensively studied by time-domain…

It is widely comprehended that temperature may cause phonon-exciton scattering, enhancing the energy level's linewidth and leading to some spectrum shifts. However, in the present paper, we suggest a different mechanism that allows the…

Mesoscale and Nanoscale Physics · Physics 2023-04-11 Duy-Nhat Ly , Dai-Nam Le , Ngoc-Hung Phan , Van-Hoang Le

Over the past few decades, thin film optoelectronic devices based on transition metal dichalcogenides (TMDs) have made significant progress. However, the sensitivity of the exciton states to environmental change presents challenges for…

Optics · Physics 2024-03-13 Shuangping Han , Pengyu Zan , Yu Yan , Yaoxing Bian , Chengbing Qin , Liantuan Xiao

We investigate the dynamics of the exciton formation and relaxation on a picosecond time scale following a pulsed photoexcitation of a semiconductor. The study is conducted in the framework of the density matrix theory complemented with the…

Mesoscale and Nanoscale Physics · Physics 2015-12-25 Veljko Janković , Nenad Vukmirović

The dynamics of exciton formation in transition metal dichalcogenides is difficult to measure experimentally, since many momentum-indirect exciton states are not accessible to optical interband spectroscopy. Here, we combine a tuneable…

Excitons are compound particles formed from an electron and a hole in semiconductors. The impact of this substructure on the phonon-exciton interaction is described by a closed system of microscopic scattering equations. To calculate the…

Mesoscale and Nanoscale Physics · Physics 2024-04-08 Manuel Katzer , Malte Selig , Andreas Knorr

The interaction between off-resonant laser pulses and excitons in monolayer transition metal dichalcogenides is attracting increasing interest as a route for the valley-selective coherent control of the exciton properties. Here, we extend…

We investigate excitonic transitions in a h-BN encapsulated monolayer $\textrm{MoS}_2$ phototransistor by photocurrent spectroscopy at cryogenic temperature (T = 5 K). The spectra presents excitonic peaks with linewidths as low as 8 meV,…

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